Timing relay



7, 1945. I K. MAHNKE 2,381,300

TIMING RELAY Filed March 13, 1943 2 Sheets-Sheet l INVENTOR Karl Mafmke.BY

A'ITORNEY Patented Aug. 7, 1945 2,381,300 TIMING RELAY Kurt Mahnke,Forest Hills, Pa., assignor to Westinghouse Electric Corporation, EastPittsburgh, Pa., a corporation of Pennsylvania Application March 13,1943, Serial No. 479,073

7 Claims.

My invention relates to electromagnetic devices and more particularly toelectromagnetic time limit devices of the direct current type.

Electromagnetic time limit devices are 'well known in the electricalart. Those depending on alternating current are usually expensivesynchronous devices and are quite accurate but those depending on directcurrent if of the inductive type have only a short variable timeconstant and if of the motor operated type are expensive and also arenot reliable as to the time constant obtained.

One object of my invention is the provision of a direct current timelimit device having a relatively long time constant and a device thatshall be cheap and easily manufactured.

Another object of my invention is the provision of a direct current timelimit relay that shall include means for adjusting the length of thetime constant and which shall have a relatively long time constant.

These objects specifically stated are merely illustrative because manyother and more specific objects will become apparent from a study of thefollowing specification and the accompanying drawings, in which:

Figure 1 is a front view of my relay;

Fig. 2 is a side view, with certain parts broken away to show somedetails, of the subject-matter shown in Fig. 1;

Fig. 3 is a circuit diagram showing my invention schematically as usedwith a direct current motor; and

Fig. 4 is a circuit diagram showing my invention schematically as usedwith an alternating current motor.

In Figures 1 and 2 of the drawings, l designates the base upon which allthe elements of my novel device are mounted. This base I is, as shown,suitably connected to the cross bars 2 and 3 for mounting the base in avertical position on a control panel board, or other structure. Mydevice has general utility but was devised with particular reference tothe needs of the United States Navy. This novel structure, in additionto being inexpensive, simple and reliable, is compact and is notmaterially affected by shocks to which war vessels, on which my devicefinds use, are often subjected.

A face plate 4 is disposed in spaced relation to the base I and is, asshown, rigidly secured to the base I. This face plate has an opening 5through which the pinion 6 projects. This pinion 5 is keyed to shaft 1to rotate with shaft 1 but may be axially adjusted on this shaft. Thepurpose of this adjustment is to obtain proper positioning of thediscrelative to the other parts of my device and to obtain some slightvariation in the time constant of my device.

Shaft 'l is freely rotatable in members 8 and 9. Member 8 is adjustablymounted in the base I and held to its adjusted position by the lock nuts9. Member 9 is rigidly secured to the face plate 4 by the bolts I0 andis held in spaced relation to face plate 4 by the spacers l I. Thespacing and adjustment of members 8 and 9 are such that shaft I is veryfreely rotatable in the members 8 and 9.

The bolts II! also hold a pair of brackets I2 and 13 of insulatingmaterial for holding the flexible, and thus movable, contact member 58and the rigid contact member 51, respectively. The face plate 4 is alsoprovided with a stud shaft l5 upon which is mounted, for free rotation,the gear sector H5. The gear teeth ll of this sector 16 meshes with thepinion 6.

The sector I6 is provided with a switch actuating stud 18, which stud,made of suitable insulation, operates to close the circuit at contactmembers 51 and 58 when the sector is rotated to its extremecounterclockwise position. A spring 20 of suitable characteristics andunder any adjusted tension is disposed between the adjusting means I4.This adjusting means comprises the bracket 49, stud bolt 48, and nut 41.The plate 9 is also provided With'a plurality of holes 45 so that roughadjustments of the tension of spring 20 may be made by shifting theupper attachment of the spring and for a finer adjustment the nut 41 maybe operated to different positions on the bolt 48.

The spring 20 normally actuates the sector IE to its extremecounterclockwise position so that the sector 16 normally rests againstthe righthand side of stop 2|. When in this position to engage stop 2!,the contact members 5'! and 58, acted upon by stud [8, are closed.

From the foregoing description of the face plate 4 and the descriptionof the elements secured to it, it is apparent that the entire face plateassembly may be removed as a unit by merely removing the screws 22 and23.

The shaft 1, shown more clearly in the cut away portion of Fig. 2, isprovided with a disc 24 of aluminum, copper, silver, or some otherconducting metal. This disc 24 is loosely mounted on the shaft and isheld in operative relation to the pinion 6, and thus the shaft 1, by thefriction clutch disc 25. This friction disc 25 is biased against thedisc 24 and thus the pinion 6 by the suitably loaded compression spring26 disposed between the friction member 25 and washer 21 loosely mountedon shaft 1 and held in axial position on shaft 1 by the pin 28. It willbe noted that the shaft and all the parts on it may be removed as aunit, after removal of the face plate 4, without affecting the positionof the other elements of the relay.

By means of suitable studs n the base I, I mount four coils, 66, 68, 69and having their axes normal to the disc 24. These coils are con nectedin series to a suitable source of direct current, a shown in Fig. 3 andas represented by the rectifier 11 in Fig. 4. To vary the flux densityof the flux disposed transverse the disc 24 the adjustable resistor orrheostat 61 is provided.

Disposed on the lower right-hand position of the base I is a voltageresponsive solenoid 29. This solenoid has a rectangular C-sh'apedconstruction with the coil 53 of the solenoid disposed within the C. Anarmature 30 is disposed within the coil and is axially moved toward theright with a rapid movement when the coil is energized. The armature isguided within the coil by suitable facing U-shaped non-magnetic guides3| and 32. This provides for free movement of the armature.

Th'e left-hand end of the armature is provided with a rod 33 guided forhorizontal movement by the lugs 34 and 35. This rod is provided with aprojecting bent arm 36 disposed to engage pin 31 on the lower arm 38 ofthe sector l6, A spring 39 of considerable strength and under tension ishooked to the rod at 40 and to a stud 4| on the base I. When thesolenoid coil is deenergized the armature moves to the left under theaction of spring 39. Thi spring 39 is selected sufiiciently strong toovercome spring so that when the solenoid coil is deenergized arm 36acting on pin 31 rotates sector |6 rapidly clockwise without rotatingdisc 24 through pinion 6. The friction disc permits this kind ofoperation.

When the solenoid coil 53 is energized arm 36 is moved to the rightwithout affecting or operating on pin 31 to alter the position of pin 31on the lower projection 38. The sector I6 is thus freed to be actuatedcounterclockwise by the spring 20. The speed of operation of the sectionI6 in the counterclockwise direction is delayed by the eddy currents indisc 24 caused by the density of the flux disposed transverse of thedisc 24.

Since the distance of the disc 24 from the adjacent ends of the coils66, 68, 69 and 10 may be varied by the axial movement of the pinion 6 bythe nuts 9', since the position of stop l8 on the sector |6 may bechanged angularly, and since the current strength of the coils 66, 68,69 and 10 may be varied by rheostat 61, and further since the tension ofspring 26 is adjustable, and also since the gear ratio between the disc24 and sector l6 can be changed, it is apparent that; the time ofmovement of sector l6 in the counterclockwise direction may be variedover a very wide range.

In many applications and particularly on board ship many automaticallyrestarting motors are connected to the same source of supply. In theevent of a voltage failure it is imperative, when voltage returns to thesupply system, that the motors or other loads be not connected to thesupply at the same time. The preferred operation is the reconnection ofthe various loads to the supply in a definite sequence. By using one ofmy relays for each of the loads and adjusting my timing relays for therespective loads for different time constants, the required sequence maybe obtained.

Assuming that motor M, Fig. 3, is in one load unit as above mentioned.For normal operation of load unit M, switch 5| is closed whereupon acircuit is established from bus 50 through switch 5|, conductor 52,solenoid coil 53 and conductor 54 to bus 55.

The armature 30 is thus rapidly moved to the right releasing the sectorI6 to the control of spring 20 and the action of coils 66, 68, 69 and10, which are also energized by the closure of switch 5|. Afte adefinite time, depending on the adjustments of nuts 9', nut 41, andrheostat 61, contact members 51 and 58 are closed.

Closure of contact members 51 and 58 establishes a circuit fromenergized conductor 52 through coil 56 of relay 56, contact members 51and 58, strip 59 and conductor 60 to bus 55. Operation of relay 56closescontact members 6| and 62. The relay is held in by contact members6| and the coil 63 of the line switch is energized and the motor M isthus connected to the buses 50 and 55 by contact members 64 and 65.

In the event of a voltage failure, all the parts move to the positionshown in Fig. 3 except that switch 5| is closed. When voltage returns onthe buses 50 and 55, the sequence above described is reenacted.

In the showing in Fig. 4, when switch 1| is closed a circuit isestablished from bus 10' through switch 1|, conductor 12, contactmembers 13, coil 53, and conductor 14 to bus 15. Another circuit isestablished from conductor 12 through contact members 16, rectifier 11to energized conductor 14. From the direct current terminals of therectifier the coils 66, 68, 69 and 10 are thus energized.

After a predetermined time, contact members 51 and 58 close whereupon acircuit is established from energized conductor 12 through coil 18 ofthe line contacto 19, strip 59 and conductor to lens 15.

Operation of line contactor 19 causes the closure of contact members BI,82, 83 and 84. The motor is thus energized and the line contactor isheld in by the circuit through contact members 84. Opening of contactmembers 13 and 16 removes the energization from the time limit relay.

Upon voltage failure, the condition of the circuits is again as shown inFig. 4 except switch 1| is closed. When the voltage comes back on thebuses the cycle above recited is repeated.

From the foregoing, it will be apparent that I have provided a simpleand eflicient time limit device which, when properly designed, canproduce any selected time constant from one second to twenty-fiveseconds, or more, particularly if the gear ratio between disc and sectoris increased.

Since both coil 53 and the magnets 66, 68, 69 and 10 are deenergizedsimultaneously, the relay will reset very fast. The disc is then turnedrapidly in clockwise direction by spring 39, without being retarded.Whether or not the clutch 25 slips is not very important for thisoperation' However, the clutch 25 is of particular value if, instead ofthe coils, permanent magnets are used for damping. In this case, spring20 should be too weak to overcome clutch friction and spring 39 shouldbe strong enough to exceed clutch friction.

My invention is not limited to the use of electromagnets but thereference characters 66, 68, 69 and 10 may as well designate permanentmagnets.

My invention is not limited to the specific showing made but is onlylimited by the scope of the claims hereto appended.

I claim as my invention:

1. A time limit device of the direct current type comprising incombination, a source of direct current, a plurality of coils connectedto said source of direct current, a base for the coils, said coils beingmounted on the base with their axes in parallel relation and so that theends of the coils fall in substantially the same plane, a rotatablymounted disc disposed a given distance from the ends of said coils androtatable in a plane parallel to the plane defined by the ends of saidcoils, disc operating means including biasing means for normally biasingsaid disc to a given angular position, electromagnetic means having aspring-biased element for operating said disc when said electromagneticmeans is deenergized to another angular position through said discoperating means, means operable by said electromagnetic means, when saidelectromagnetic means is energized, to release said disc operating meansto thus release said disc for rotation to its first given angularposition, said disc, being in the magnetic field of said coils, is thusretarded in its rotation to a selected speed for a selected period oftime; and switching means operable by said disc at the end of itsrotation to its first angular position.

2. A time limit device of the direct current type comprising incombination, a source of direct current, a plurality of coils connectedto said source of direct current, a base for the coils, said coils beingmounted on the base with their axes in parallel relation and so that theends of the coils fall in substantially the same plane, a rotatablymounted disc disposed a given distance from the ends of said coils androtatable in a plane parallel to the plane defined by the ends of saidcoils, means for adjusting the distance of the disc from the ends of thecoils, disc operating means including biasing means for normally biasingsaid disc to a given angular position, electromagnetic means having aspring-biased element for operating said disc through said discoperating means to another angular position when said electromagneticmeans is deenergized, means operable by said electromagnetic means, whensaid electromagnetic means is energized, to release said disc operatingmeans to thus release said disc for rotation to its first given angularposition, said disc, being in the magnetic field of said coils, is thusretarded in its rotation to a selected speed for a selected period oftime, and switching means operable by said disc at the end of itsrotation to its first angular position.

3. A time limit device of the direct current type comprising incombination, a source of direct current, a plurality of coils connectedto said source of direct current, a base for said coils, means foradjusting the current traversing said coils to thus alter the fiuxdensity at the ends of said coils, said coils being mounted on the basewith their axes in parallel relation and so that the ends of the coilsfall in substantially the same plane, a rotatably mounted disc disposeda given distance from the ends of said coils and rotatable in a planeparallel to the plane defined by the ends of said coils, disc operatingmeans including biasing means for normally biasing said disc to a givenangular position, electromagnetic means having a spring-biased elementfor operating said disc through said disc operating means to anotherangular position when said electromagnetic means is deenergized, meansoperable by said electromagnetic means, when said electromagnetic meansis energized, to release said disc operating means to thus release saiddisc for rotation to its first given angular position, said disc, beingdisposed in the magnetic field of said coils, is thus retarded in'itsrotation to a selected speed for a selected period of time, andswitching means operable by said disc at the end of its rotation to itsfirst angular position.

4. A time limit device of the direct current type. comprising incombination, a source of direct current, a plurality of coils connectedto said source of direct current, a base for said coils, means foradjusting the current traversing said coils to thus alter the fluxdensity at the ends of said coils, said coils being mounted on the basewith their axes in parallel relation and so that the ends of the coilsfall in substantially the same plane, a rotatably mounted disc disposeda given distance from the ends of said coils and rotatable in a planeparallel to the plane defined by the ends of said coils, disc operatingmeans including biasing means for normally biasing said disc to a givenangular position, means for adjusting the biasing force of said .discbiasing means, electromagnetic means having a spring-biased element foroperating said disc through said disc operating means to another angularposition when said electromagnetic means is deenergized, means operableby said electromagnetic means, when said electromagnetic means isenergized, to release said disc operating means to thus release saiddisc for rotation to its first given angular position, said disc, beingdisposed in the magnetic field of said coils, is thus retarded in itsrotation to a selected speed for a selected period of time, andswitching means operable by said disc at the end of its rotation to itsfirst angular position.

5. A time limit device of the direct current type comprising incombination, a source of direct current, a plurality of coils connectedto said source of direct current, a base for said coils, means foradjusting the current traversing said coils to thus alter the fluxdensity at the ends of said coils, said coils being mounted on the basewith their axes in parallel relation and so that the ends of the coilsfall in substantially the same plane, a rotatably mounted disc disposeda given distance from the ends of said coils and rotatable in a planeparallel to the plane defined by the ends of said coils, means foradjusting the distance of the disc from the ends of the coils, discoperating means including biasing means for normally biasing said discto a given angular position, electromagnetic means having a springbiased element for operating said disc through said disc operating meansto another angular position when said electromagnetic means isdeenergized, means operable by said electromagnetic means to releasesaid disc operating means to thus release said disc for rotation to itsfirst given angular position, said disc, being disposed in the magneticfield of said coils, is thus retarded in its rotation to a selectedspeed for a selected period of time, and switching means operable bysaid disc 'at the end of its rotation to its first angular position.

6. A time limit device of the direct current,

type comprising in combination, a source of direct current, a pluralityof coils connected to said source of, direct current, a base for saidcoils, means for adjusting the current traversing said coils to thusalter the flux density at the ends of said coils, said coils beingmounted on the base with their axes in parallel relation and so that theends of the coils fall in substantially the same plane, a rotatablymounted disc disposed a given distance from the ends of Sflildi coilsand rotataliilev in a plane parallel to the plane defined by the ends ofsaid coils, disc operating means including biasing means for normallybiasing said disc to a given angular position, means for adjusting thebiasing force of said disc biasing means, electromagnetic means having aspring-biased element for operating said disc: through said discoperating means to another angular position when said electromagneticmeans is deenerg'imd, means operable by said electromagnetic means torelease said disc operating means to thus release said: disc forrotation to its first given angular position, said being disposed in themagnetic field oi! said coils, is thus retarded in its rotation to aselected speed for a selected period of time, and switchhug meansoperable by said disc at the end of its rotation to its firstangularposition.

7. A time limit device of the direct current type comprisingcombination, a source of direct current, a plurality 0t coils connectedto said sum-cc of direct current, a base for said coils, means foradjusting the current traversing said coils to thus alter the fluxdensity at the ends of said coils, said coils being mounted on the basewith their axes in parallel relation and so that the ends of the coilsfall in substantially the same plane, a rotatably mounted disc disposeda given distance from the ends of said coils and rotatable in a planeparallel to the plane defined by the ends of said coils, means foradjusting the distance of the disc from the ends of the coils, discoperating means including biasing means for normally biasing said discto a given angular position, means for adjusting the biasing force: ofsaid disc biasing means, electromagnetic meansv having a spring-biasedelement for operating said disc through said disc operating means toanother angular position when said electromagnetic means is deenerglzed,means. operable by said electromagnetic means to release said discoperating means to thus release said disc for rotation to its firstgiven angular position, said disc, being disposed in the magnetic fieldof saidcoils, is thus retarded in its rotation to a selected speed for aselected period of time, and switching means operable by said disc atthe end of its rotation to its first angular position.

KURT MAHNKE.

